Date and Time Calculators
Calculate calendar dates, week numbers, Unix timestamps, and time-zone conversions with tools built for quick answers and repeat use.
Days Calculator
Count days between dates, add or subtract days, and answer common “days from today” questions.
Week Number Calculator
Find the current ISO week, look up week numbers by date, and browse full week ranges for a year.
Unix Timestamp Converter
Convert epoch seconds, milliseconds, microseconds, and nanoseconds into readable dates and back.
Time Zone Converter
Compare times across world time zones and avoid daylight-saving scheduling mistakes.
Interactive Calendar
Browse months and years, inspect date details, and check day-of-year and week-number values.
Common Calculation Tasks
How the Calculators Handle “Today”
Questions based on today’s date render a fresh UTC answer first, then update in your browser from your current device date and time zone. This avoids frozen dates while keeping the visible answer aligned with where you are.
Which Calculator Should You Start With?
Planning a deadline: use the days calculator first, then check the result on the calendar to see the weekday and surrounding dates.
Working with reports: use the week number calculator to confirm the ISO week year and date range before counting days.
Debugging logs or APIs: use the Unix timestamp converter to decode the value, then compare UTC and local outputs.
Scheduling across countries: use the time zone converter before sending the time, especially around daylight saving changes.